in a neo-classical and impressionist vein, you have:
Sonata, By Prokofiev. Tender/Playful. A personal favorite and that recording sounds great!!
I recommend the
finale and the scherzo for some extremely FUN music.
Sonata,, by Francis Poulenc. Cut of the same cloth as the Prokofiev one, I feel
Pierre Sancan's
sonatine, (gorgeous little piece) Henry Dutilleux's
sonatine
Boulez also wrote a sonatine. And don't forget Messiaen's
La Merle Noir. (they both sound more ''contemporary'')
You should have no problem finding any of these. People hold them in quite high regard, generally speaking.
edit: I came across
this by chance. Pretty cute!